This application claims the priority of European Application No. 97106621.2, filed Apr. 22, 1997, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a lamella groove milling tool and, more particularly, to a lamella groove milling tool having a housing with a motor, a cutter coupled with the motor by way of a gear, a longitudinally displaceable carriage having an opening for the emerging of the cutter, and a plane support surface, as well as a stop plate, which can be adjusted concerning the distance and the angle with respect to the milling plane formed by the cutter.
Lamella groove milling tools are used for making grooves into which lamellae are inserted as connection elements between wood elements. This connecting technique results in very stable and stiff connections which have a high strength.
A lamella groove milling tool of this type is known, for example, from European Patent document EP 0 420 498. In it, a lamella groove milling tool is described which consists of a housing having a motor. The motor drives a rotatable cutter which can be moved out of and withdrawn into an opening of a sliding subassembly connected with the housing. In this case, the sliding subassembly and the housing are movably arranged with respect to one another, whereby the cutter is movably arranged in the so-called sectional plane with respect to the opening of the sliding subassembly. The sliding subassembly has a surface area which is aligned in parallel to the sectional plane and a stop face which is aligned perpendicularly thereto and in which the mentioned opening is arranged. The distance between the surface area and the sectional plane, as a rule, is selected according to the standard distance defined for groove-type connections and cannot be changed. In order to now produce a groove at a distance which differs from the standard distance with respect to an edge on a workpiece to be machined, another stop plate is also provided on the stop face and can be swivelled with respect to the stop face in an angular range of 90.degree., the distance between the swivelling axis and the sectional plane being adjustable. However, for implementing these grooves, the tool must be held or guided in a swivelled manner.
The disadvantage of this known construction of a lamella groove milling tool is the fact that, on the one hand, it requires relatively high expenditures to maintain the permissible tolerance with respect to the distance between the sectional plane and the surface area and, on the other hand, for all groove machining which deviates from the standard distance, the use of the adjustable stop face is required. This results in high expenditures and, as the result of the construction of this stop face, is also connected with high tolerances, particularly where a large number of pieces require the machining of grooves. In addition, an adjustment which was selected and was then changed can no longer be reproduced in a precise manner.
It is an object of the present invention to find a lamella groove milling tool of the above-described type which can be adapted in a simple and fast manner to different application requirements.
According to the invention, this object is achieved by a lamella groove milling tool having a housing with a motor, a cutter coupled with the motor by way of a gear, a longitudinally displaceable carriage having an opening for the emerging of the cutter, and a plane support surface, as well as a stop plate, which can be adjusted concerning the distance and the angle with respect to the milling plane formed by the cutter. The cutter is arranged on a drive shaft which is essentially vertically displaceable along its axis with respect to the support surface.
In the case of the lamella groove milling tool further developed according to the invention, the distance between the milling plane and the support surface can advantageously be adjusted. On the one hand, the manufacturing of the lamella groove cutting tool can be simplified in this manner in that the distance to be maintained within a certain tolerance can be adjusted in the factory in the case of the finished tool by a corresponding positioning of the drive shaft in a very simple manner. This eliminates the conventionally required interventions into the tools not meeting the tolerance. Further, the user can also freely select a basic distance which differs from the provided and adjusted standard distance and is advantageous according to the application.
Special embodiments of the invention are further described herein.
Another advantage of the present invention is the fact that different adjustments can be reproduced an arbitrary number of times with high precision by means of the preferred embodiment with the lockable discrete adjusting devices. This was not so in the case of the conventionally known devices where the adjustments took place without exception in a continuous manner and one clamping fixation respectively was used. As a result of the fact that, according to the invention, lockable, that is, discrete positions can be adjusted, any selected position can be reproduced again and again in a precise and reliable manner. This also leads to a higher precision during the machining of the workpieces. In addition, a desired position can also be adjusted more rapidly since the respective detent position is precisely indicated and a continuously adjustable marking must not be coordinated with an adjusting scale.